The social media account for the US snack Pop Tarts replied: “I appreciate your savagery these days”.

While many enjoyed the promotion, some customers complained about the app not working when they tried to take up the offer.

One person, Alex Shaw, tweeted in response: “Too bad I can’t use it because your app won’t connect to the internet.”

While someone else said: “It would be great if it actually worked. Been sitting at McDonalds for 5minutes for nothing.”

Others said that Burger King’s promotion backfired and they ended up eating in McDonald’s.

Another customer, Sten Drescher, wrote: “I wanted to take you up on this offer, but once I reached McDonald’s, I discovered that none of the nearby Burger Kings did mobile ordering, a requirement of this offer. So we got burgers at McDonald’s since we were already there!”